A high permeability inductor sintering material

Abstract

This invention discloses a high-permeability inductor sintering material in the field of inductor sintering material technology. Its preparation process includes the following steps: S1, preparing LiMn6Sn6 single-crystal material; S2, primary ball milling; S3, pre-sintering; S4, secondary ball milling; S5, granulation; S6, secondary sintering. By introducing LiMn6Sn6 single-crystal material, this invention promotes ferromagnetic coupling between Mn3 layers and magnetic coupling between Sn2Li and Mn3 layers through superexchange interactions, enhancing the long-range ferromagnetic order of the sintered material and significantly improving its permeability. The doping of LiMn6Sn6 single-crystal material promotes grain growth in the sintered material through grain boundary phases, making the crystal structure more compact, increasing the overall density, optimizing the microstructure of the material, and reducing eddy current losses. Secondary ball milling effectively disperses any potential agglomerates, increasing the specific surface area of ​​the powder. The addition of sodium bismuthate and sodium molybdate, which have low melting points, helps to improve the density of the sintered material, further enhancing its overall performance.

Description

Technical Field

[0001] This invention belongs to the technical field of inductor sintering materials, and particularly relates to a high-permeability inductor sintering material. Background Technology

[0002] Against the backdrop of rapid development in modern electronic technology, inductors, as key passive electronic components, play a crucial role in various electronic fields such as electronic communication equipment, power management, and radio frequency identification (RFID) systems. Inductors are primarily responsible for tasks such as filtering, energy storage, signal transmission, and maintaining electromagnetic compatibility. As electronic devices develop towards miniaturization, integration, and high performance, the performance requirements for inductors are also increasing.

[0003] To meet the miniaturization requirements of integrated circuits, high-inductance devices must be implemented within a limited space, making inductor size a major factor restricting circuit integration and miniaturization. Therefore, developing planar thin-film inductors capable of operating at high frequencies and possessing high permeability has become a key technological path driving the further development of electronic devices. However, existing inductor sintering materials generally suffer from insufficient permeability, high porosity, and uneven grain growth, which severely limit the improvement of inductor performance and the expansion of its application range. Summary of the Invention

[0004] In view of the above situation and to overcome the defects of the prior art, the present invention aims to provide a high permeability inductor sintering material. This material not only has high permeability, but also effectively reduces porosity and improves the density and overall performance of the material. The present invention proposes to introduce single crystal material and improve the permeability of the sintered material by means of secondary ball milling and secondary sintering.

[0005] To achieve the above objectives, the following technical solution is adopted: This invention provides a high-permeability inductor sintering material, which is prepared through the following steps:

[0006] S1. Preparation of LiMn6Sn6 single crystal material: Lithium, manganese and tin metals are weighed in the corresponding molar ratio under an argon atmosphere and then added to a quartz tube. Flux is added at 5% of the total mass of the metals. The quartz tube is then placed in a high-temperature furnace and heated gradually to form a homogeneous melt. The flux is separated by a centrifuge and then cooled by controlling the cooling rate to obtain LiMn6Sn6 single crystal material.

[0007] S2. One-time ball milling: After weighing iron oxide, zinc oxide, nickel oxide, copper oxide, aluminum oxide, cobalt oxide, silicon dioxide and LiMn6Sn6 single crystal material in proportion, the raw materials are thoroughly mixed in a ball mill and then dried.

[0008] S3. Pre-sintering: The mixed powder dried after one ball milling is pre-sintered under a nitrogen atmosphere;

[0009] S4. Secondary ball milling: Add the pre-sintered material together with sodium bismuthate and sodium molybdate to a ball mill for secondary ball milling to promote uniform mixing of the materials.

[0010] S5. Granulation: Mix the PVA glue with the material from the secondary ball milling, then grind it, and then pour it into a mold to press and shape it.

[0011] S6. Secondary sintering: The pressed material is placed in a sintering furnace and sintered under a protective atmosphere. After sintering, it is naturally cooled to obtain the inductor sintered material.

[0012] Furthermore, the inductor sintering material comprises the following raw material components by mass percentage: 55-65% iron oxide, 12-22% zinc oxide, 10-25% nickel oxide, 1-8% copper oxide, 1-5% aluminum oxide, 0.5-5% cobalt oxide, 0.5-3% silicon dioxide, 1-10% LiMn6Sn6 single crystal material, 1.5-3% sodium bismuthate, and 1.5-3% sodium molybdate.

[0013] Furthermore, the molar ratio of lithium, manganese, and tin is 0.85-1.15:6-8.5:7-9.

[0014] Furthermore, the flux is one of magnesium oxide, bismuth oxide, and calcium oxide.

[0015] Furthermore, in step S1, the heating rate is 20-50℃ / min, the maximum temperature is 1100-1300℃, and the cooling rate is 40-80℃ / min.

[0016] Furthermore, in step S2, the ball milling time is 3-6 hours, the ball milling speed is 200-500 r / min, and the temperature is room temperature.

[0017] Furthermore, the pre-sintering temperature in step S3 is 850-1000℃, and the time is 2-5h.

[0018] Furthermore, the secondary ball milling time in step S4 is 1-3 hours, the ball milling speed is 100-300 r / min, and the temperature is 50-100℃.

[0019] Furthermore, the amount of PVA adhesive added is 10%-20% of the total mass of the raw materials.

[0020] Furthermore, the sintering temperature in step S6 is 750-1000℃, and the time is 3-6h.

[0021] The beneficial effects of this invention are:

[0022] (1) This invention improves the magnetic permeability of sintered materials by introducing LiMn6Sn6 single crystal material into the raw materials of sintered materials. The two Sn2 honeycomb layers sandwiched between two Mn3 layers in the LiMn6Sn6 single crystal material promote the ferromagnetic coupling between Mn3-Mn3 layers through superexchange interaction. At the same time, the magnetic coupling between Sn2Li and Mn3 layers enhances the long-range ferromagnetic ordered state of the sintered material, thereby increasing the magnetic permeability of the sintered material.

[0023] (2) The doping of LiMn6Sn6 single crystal material not only improves the permeability, but also promotes the growth of grains in the sintered material through the generated grain boundary phase, making the crystal structure more compact, reducing the porosity and increasing the overall density. This structural optimization reduces the resistance to magnetic domain movement and domain wall displacement, reduces coercivity, further increases the permeability, and effectively reduces eddy current loss and energy loss.

[0024] (3) The present invention adopts a secondary ball milling process, which effectively disperses the possible agglomerates, increases the specific surface area of ​​the powder, thereby improving the mixing uniformity of the material. In the secondary ball milling process, sodium bismuthate and sodium molybdate with low melting points are added. These substances penetrate into the voids of the material during the secondary sintering process, which helps to improve the density of the sintered material and further enhances the overall performance of the material. Attached Figure Description

[0025] Figure 1 The permeability curves of various embodiments and comparative examples of a high permeability inductor sintering material of the present invention are shown.

[0026] Figure 2 The magnetic loss test results are shown for various embodiments and comparative examples of the high permeability inductor sintering material of the present invention.

[0027] Figure 3 The density test results of various embodiments and comparative examples of the high permeability inductor sintering material of the present invention are shown.

[0028] Figure 4 The current measurement results for various embodiments and comparative examples of a high-permeability inductor sintering material of the present invention, with an inductance reduced by 30%.

[0029] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the embodiments of the invention to explain the invention and do not constitute a limitation thereof. Detailed Implementation

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those familiar to those skilled in the art. Furthermore, any methods and materials similar to or equivalent to those described herein may be applied to this invention. The preferred embodiments and materials described herein are for illustrative purposes only and do not limit the scope of this application.

[0032] Unless otherwise specified, the experimental methods used in the following examples are conventional methods. Unless otherwise specified, the experimental materials used in the following examples were all purchased from commercial sources. Example

[0033] A high permeability inductor sintering material

[0034] The inductor sintering material is prepared through the following steps:

[0035] S1. Preparation of LiMn6Sn6 single crystal material: Lithium, manganese and tin metals are weighed in the corresponding molar ratio under an argon atmosphere and then added to a quartz tube. Flux is added at 5% of the total mass of the metals. The quartz tube is then placed in a high-temperature furnace and heated gradually to form a homogeneous melt. The flux is separated by a centrifuge and then cooled by controlling the cooling rate to obtain LiMn6Sn6 single crystal material.

[0036] S2. One-time ball milling: After weighing iron oxide, zinc oxide, nickel oxide, copper oxide, aluminum oxide, cobalt oxide, silicon dioxide and LiMn6Sn6 single crystal material in proportion, the raw materials are thoroughly mixed in a ball mill and then dried.

[0037] S3. Pre-sintering: The mixed powder dried after one ball milling is pre-sintered under a nitrogen atmosphere;

[0038] S4. Secondary ball milling: Add the pre-sintered material together with sodium bismuthate and sodium molybdate to a ball mill for secondary ball milling to promote uniform mixing of the materials.

[0039] S5. Granulation: Mix the PVA glue with the material from the secondary ball milling, then grind it, and then pour it into a mold to press and shape it.

[0040] S6. Secondary sintering: The pressed material is placed in a sintering furnace and sintered under a protective atmosphere. After sintering, it is naturally cooled to obtain the inductor sintered material.

[0041] The inductor sintering material comprises the following raw material components by mass percentage: 55% iron oxide, 20% zinc oxide, 10% nickel oxide, 4% copper oxide, 5% aluminum oxide, 1% cobalt oxide, 1% silicon dioxide, 1% LiMn6Sn6 single crystal material, 1.5% sodium bismuthate, and 1.5% sodium molybdate.

[0042] The molar ratio of lithium, manganese, and tin is 0.85:6:7.

[0043] The flux is magnesium oxide.

[0044] The heating rate in step S1 is 20℃ / min, the maximum temperature is 1100℃, and the cooling rate is 40℃ / min.

[0045] The ball milling time in step S2 is 3 hours, the ball milling speed is 200 r / min, and the temperature is room temperature.

[0046] The pre-sintering temperature of step S3 is 850℃, and the time is 2 hours.

[0047] The secondary ball milling time in step S4 is 1 hour, the ball milling speed is 100 r / min, and the temperature is 50℃.

[0048] The amount of PVA adhesive added is 10% of the total mass of the raw materials.

[0049] The sintering temperature in step S6 is 750℃, and the time is 3 hours. Example

[0050] A high permeability inductor sintering material

[0051] The preparation steps of the inductor sintering material are the same as in Example 1.

[0052] The inductor sintering material comprises the following raw material components by mass percentage: 65% iron oxide, 15% zinc oxide, 12% nickel oxide, 1.5% copper oxide, 1.5% aluminum oxide, 0.5% cobalt oxide, 0.5% silicon dioxide, 1% LiMn6Sn6 single crystal material, 1.5% sodium bismuthate, and 1.5% sodium molybdate.

[0053] The molar ratio of lithium, manganese, and tin is 1.15:8.5:9.

[0054] The flux is bismuth oxide.

[0055] The heating rate in step S1 is 50℃ / min, the maximum temperature is 1300℃, and the cooling rate is 80℃ / min.

[0056] The ball milling time in step S2 is 6 hours, the ball milling speed is 500 r / min, and the temperature is room temperature.

[0057] The pre-sintering temperature of step S3 is 1000℃, and the time is 5h.

[0058] The secondary ball milling time in step S4 is 3 hours, the ball milling speed is 300 r / min, and the temperature is 100℃.

[0059] The amount of PVA adhesive added is 20% of the total mass of the raw materials.

[0060] The sintering temperature in step S6 is 1000℃, and the time is 6 hours. Example

[0061] A high permeability inductor sintering material

[0062] The preparation steps of the inductor sintering material are the same as in Example 1.

[0063] The inductor sintering material comprises the following raw material components by mass percentage: 60% iron oxide, 12% zinc oxide, 12% nickel oxide, 3% copper oxide, 3% aluminum oxide, 1% cobalt oxide, 1% silicon dioxide, 4% LiMn6Sn6 single crystal material, 2% sodium bismuthate, and 2% sodium molybdate.

[0064] The molar ratio of lithium, manganese, and tin is 1.05:7.5:8.

[0065] The flux is calcium oxide.

[0066] The heating rate in step S1 is 30℃ / min, the maximum temperature is 1200℃, and the cooling rate is 50℃ / min.

[0067] The ball milling time in step S2 is 5 hours, the ball milling speed is 300 r / min, and the temperature is room temperature.

[0068] The pre-sintering temperature in step S3 is 900℃, and the time is 3.5h.

[0069] The secondary ball milling time in step S4 is 2 hours, the ball milling speed is 200 r / min, and the temperature is 80℃.

[0070] The amount of PVA adhesive added is 15% of the total mass of the raw materials.

[0071] The sintering temperature in step S6 is 850℃, and the time is 4.5h.

[0072] Comparative Example 1

[0073] The difference between this comparative example and Example 3 is that the raw material composition of the inductor sintering material does not contain LiMn6Sn6 single crystal material, but is replaced by the remaining components in the raw material composition in equal amounts. The remaining components, component content, and preparation process are the same as in Example 3.

[0074] Comparative Example 2

[0075] The difference between this comparative example and Example 3 is that sodium bismuthate and sodium molybdate were not added during the second ball milling. The remaining components, component contents, and preparation process are the same as in Example 3.

[0076] Results Analysis

[0077] Copper wire was selected, with N = 26 Ts turns. The inductance of each embodiment and comparative example, as well as the inductance value under superimposed current, were measured using a YG107A magnetic ring turn count tester. The test frequency was 0-100MHz. The permeability at different test frequencies was calculated using the permeability calculation formula. The permeability curves are shown in [Figure / Reference]. Figure 1 .

[0078] pass Figure 1 It can be seen that the permeability of inductor sintering materials with the introduction of LiMn6Sn6 single crystal material and inductor sintering materials with the addition of sodium bismuthate and sodium molybdate during secondary ball milling are both improved.

[0079] The magnetic losses of each embodiment and comparative example were measured using the AC power method according to TCPSS1009-2020. The samples were prepared with dual windings. The test results are shown in [Figure number missing]. Figure 2 .

[0080] The density of each embodiment and comparative example was measured according to the measurement method in GB / T 3850-2015. The measurement results are shown in [Figure number missing]. Figure 3 .

[0081] The current values ​​of each embodiment and comparative example with a 30% decrease in inductance were measured using an E4980A LCR meter. The results are shown in [Figure number missing]. Figure 4 .

[0082] pass Figure 2-4 In summary, the sintered materials of each embodiment have fewer voids and higher density. Furthermore, each embodiment exhibits lower magnetic loss under high-frequency excitation, and the current value of the inductance is higher even with a 30% decrease in inductance. This demonstrates that the addition of LiMn6Sn6 single crystal material, sodium bismuthate, and sodium molybdate helps to improve the density of the inductor sintered material, thereby reducing coercivity, magnetic loss, and power consumption.

[0083] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

[0084] The present invention and its embodiments have been described above. This description is not restrictive, and the accompanying drawings are only one embodiment of the present invention. The actual application is not limited to this. In conclusion, if those skilled in the art are inspired by this description and design similar methods and embodiments without departing from the spirit of the present invention, they should all fall within the protection scope of the present invention.

Claims

1. A high-permeability inductor sintering material, characterized in that: The inductor sintering material is prepared through the following steps: S1. Preparation of LiMn6Sn6 single crystal material: Lithium, manganese and tin metals are weighed in the corresponding molar ratio under an argon atmosphere and then added to a quartz tube. Flux is added at 5% of the total mass of the metals. The quartz tube is then placed in a high-temperature furnace and heated gradually to form a homogeneous melt. The flux is separated by a centrifuge and then cooled by controlling the cooling rate to obtain LiMn6Sn6 single crystal material. S2. One-time ball milling: After weighing iron oxide, zinc oxide, nickel oxide, copper oxide, aluminum oxide, cobalt oxide, silicon dioxide and LiMn6Sn6 single crystal material in proportion, the raw materials are thoroughly mixed in a ball mill and then dried. S3. Pre-sintering: The mixed powder dried after one ball milling is pre-sintered under a nitrogen atmosphere; S4. Secondary ball milling: Add the pre-sintered material together with sodium bismuthate and sodium molybdate to a ball mill for secondary ball milling to promote uniform mixing of the materials. S5. Granulation: Mix the PVA glue with the material from the secondary ball milling, then grind it, and then pour it into a mold to press and shape it. S6. Secondary sintering: The pressed material is placed in a sintering furnace and sintered under a protective atmosphere. After sintering, it is naturally cooled to obtain the inductor sintered material. The raw material components, by mass percentage, are as follows: iron oxide 55-65%, zinc oxide 12-22%, nickel oxide 10-25%, copper oxide 1-8%, aluminum oxide 1-5%, cobalt oxide 0.5-5%, silicon dioxide 0.5-3%, LiMn6Sn6 single crystal material 1-10%, sodium bismuthate 1.5-3%, and sodium molybdate 1.5-3%.

2. The high permeability inductor sintering material according to claim 1, characterized in that: The molar ratio of lithium, manganese, and tin is 0.85-1.15:6-8.5:7-9.

3. The high permeability inductor sintering material according to claim 2, characterized in that: The flux is one of magnesium oxide, bismuth oxide, and calcium oxide.

4. The high permeability inductor sintering material according to claim 3, characterized in that: The heating rate in step S1 is 20-50℃ / min, the maximum temperature is 1100-1300℃, and the cooling rate is 40-80℃ / min.

5. The high permeability inductor sintering material according to claim 4, characterized in that: The ball milling time in step S2 is 3-6 hours, the ball milling speed is 200-500 r / min, and the temperature is room temperature.

6. The high permeability inductor sintering material according to claim 5, characterized in that: The pre-sintering temperature of step S3 is 850-1000℃, and the time is 2-5h.

7. The high permeability inductor sintering material according to claim 6, characterized in that: The secondary ball milling time in step S4 is 1-3 hours, the ball milling speed is 100-300 r / min, and the temperature is 50-100℃.

8. The high permeability inductor sintering material according to claim 7, characterized in that: The amount of PVA adhesive added is 10%-20% of the total mass of the raw materials.

9. The high permeability inductor sintering material according to claim 8, characterized in that: The sintering temperature in step S6 is 750-1000℃, and the time is 3-6 hours.

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